The present invention relates to an imaging device and an image synthesis program.
High dynamic range (HDR) imaging techniques known in the art use a plurality of images of the same subject having both a dark area and a bright area captured under different exposures so that such images can be synthesized into a single composite image without the dark area being crushed black and the bright area including blown-out highlights (refer to, for example, Japanese Laid-Open Patent Publication No. 2003-319240).
Such HDR imaging techniques conventionally require a plurality of images captured under different exposures to undergo position corrections before the images are synthesized into a single composite HDR image.
The position corrections of the captured images are typically performed by extracting the contour of the subject in each image and comparing the contours extracted from the different images. However, the images captured under different exposures often fail to have the same contours that can be extracted easily. This requires processing for predicting positional differences between the images. Such processing requires additional time.